But it may attempt to amend legislation to ensure Prime Minister Theresa May lets Parliament scrutinise any deal with the EU before it is signed.

The Lords has begun a series of debates on the Government’s European Union (Notification of Withdrawal) Bill, which allows Prime Minister Theresa May to begin the process of quitting the European Union, after it was approved by the House of Commons earlier this month.

Debates are expected to stretch into the early hours of the morning. Members of the House of Lords will conclude two days of lengthy debates on Tuesday night - or possibly the early hours of Wednesday morning, if discussions continue past midnight.

And there will be further discussions on Monday February 27 and Wednesday March 1, when the Lords will vote on amendments to the legislation.

The Government will oppose any amendments to the Bill but there is a possibility it could be defeated because it does not have a majority in the Lords.

This would lead to what is known as “ping pong”, with the legislation sent back to the Commons - which would almost certainly vote to remove the amendments and then send it back to the Lords.

Lord John Shipley, former leader of Newcastle City Council and Liberal Democrat Councillor

However, Labour’s leader in the Lords, Baroness Smith of Basildon, said she did not expect this process to last long, suggesting that Labour members of the Lords would swiftly admit defeat.

She told the BBC: “All the House of Lords can do is ask the Commons to look at an issue again. I don’t see any extended ping pong on this at all.”

Around 190 peers are expected to speak during the two days set aside for the European Union (Notification Of Withdrawal) Bill’s second reading debate in the Lords, the first time the upper chamber will debate the legislation.

Mr Brown sent rebel Labour MPs a letter titled “formal written reprimand.” It set out the divisions where they voted “contrary to the decision of the Shadow Cabinet” and said: “You are requited to comply with the whip in the future.”

One of those to receive the letter, London MP David Lammy, posted a copy on Twitter and said: “Just received a formal reprimand from the Chief Whip. Thanks, but this was a matter of conscience. I would do it again without hesitation.”

Prime Minister Theresa May sits behind the Speaker (back row) as Baroness Smith of Basildon speaks in the House of Lords, London, during a debate on the Brexit Bill (Image: PA)

Prime Minister Theresa May entered the House of Lords and listened to the early stages of the debate from inside the Chamber, sitting on the steps of the throne used by the Queen during the State Opening of Parliament.

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While she is entitled to do this as a member of the Queen’s Privy Council, it is extremely rare for the Prime Minister, or any MP, to listen to Lords debates from inside the Chamber itself.

Speaking before the debate, Mrs May urged peers not to delay Brexit.

Asked whether the House of Lords vote might delay the process, she said: “When the Bill to allow the Government to trigger Article 50 to start the Brexit process went through the House of Commons it went through with good majorities.

“It was not amended.

“I hope that the House of Lords will pay attention to that.

“Properly there will be debate and scrutiny in the House of Lords, but I don’t want to see anybody holding up what the British people want, what the people of Stoke-on-Trent voted for last year, which is for us to deliver Brexit, to leave the European Union.”